1. Technical Field
The presently disclosed subject matter relates to a vehicle lamp to be used as various types of lamps intended for a vehicle, such as a vehicle position lamp.
2. Description of the Related Art
In recent years, automobile and vehicle design has shifted to forms in which the four corners of the vehicle body are cut away obliquely and to a larger extent as compared to previous designs.
Vehicle lamps that are to be mounted near the four corners of the vehicle body are therefore shaped to wrap around these body portions, and even the fender area of the vehicle body. Accordingly, even if light guide lenses are provided on the light sources, this new structure and design has made it difficult for the outermost ends (outside ends) of the light guide lenses of the vehicle lamps to emit light.
In addition, in order to differentiate the vehicle lamps from conventional lamps in appearance, demand has been increasing for vehicle-lamp designs using a so-called solid-looking lens and crystalline-looking lens.
Vehicle lamps that can satisfy such demand, however, can be difficult to configure.
Vehicle lamps using a light guide lens are disclosed, for example, in Japanese Patent Application Laid-Open Nos. 2002-324418 (corresponding to U.S. Pat. No. 6,652,129 B2) and 2006-164908 (corresponding to U.S. Patent Publication No. 2006/0146555A1).
In view of installation space, both the vehicle lamps disclosed in the conventional art references set forth above are configured so that light emitted forward from a light source is directed by the light guide lens to the back of the light source so that the light guide lens emits light.
Nevertheless, in vehicle lamps having such configurations, the amount of light incident on the light guide lens is small, and therefore the light guide lens looks dim when the light guide lens is observed from outside of the vehicle.
In addition to this, with the structure of utilizing total reflection inside the light guide lens to emit light in a lateral direction with respect to the direction of incidence of the light from the light source, light loss increases since the light emitted from the end face of the light guide lens is unused.
As for the demand for vehicle-lamp designs using a solid-looking lens or crystalline-looking lens, prisms intended to emit light sideways by utilizing total reflection inside the light guide lens may be used. However, since these prisms look like a reflecting surface when observed from the light emission side, it is difficult for conventional light guide lenses to provide a crystalline look.
Furthermore, since such light guide lenses are intended for uniform light emission or so-called plane emission, it is difficult to provide a distinctive appearance in light emission.